Why Are Corals Crucial to Fish?
Our aim is to raise awareness of coral reefs and the threats they face. Coral reefs are bleaching and dying, and therefore so many delicate and diverse ecosystems around the world are under threat. But, in order to fully understand how significant this is, we need to understand the importance of coral reefs to so many lives.
You probably have read that coral reefs are home to a quarter of ocean life. This is a fact mentioned in so many different articles and websites, from the World Wide Fund for Nature to the National Oceanic and Atmospheric Administration. Seeing as that coral reefs occupy less than one percent of the ocean floor, this is a lot of biodiversity!
Marine life relies on coral reefs for so many different things, from food to protection. A lot of these relationships are symbiotic, meaning that the fish help the corals and vise versa. In this article, we will look at how fish rely on coral reefs in order to understand just how important these ecosystems are for the planet.
Coral as Food
Some species of fish rely on coral for food and these fish are referred to as corallivore. One type of fish that feeds on coral is the butterflyfish. These beautiful and colorful fish and are only found in coral reefs. According to the Coral Reef Alliance, some species of butterflyfish eat the mucus off hard corals. This is normally their primary food source, and it provides them with a lot of energy and nutrients. Other butterflyfish will feed on coral polyps or small invertebrates.
Without coral reefs, we will lose the 129 species of butterflyfish. There will be no food for them and no home.
Another species of corallivore fish are parrotfish. Parrotfish are really interesting creatures, appearing with a variety of bright colors and patterns. According to National Geographic, they also change sex multiple times throughout their lives. These fish will mostly feed off of coral, spending most of their days grazing on the corals. They have big teeth that allow them to scrape the coral, feeding on the coral’s tissue and skeleton. They also feel off of bacteria and the zooxanthellae that can be found in the coral’s tissue.
These fish rely on the corals for food, using them as their main source of nutrients. However, the corals sometimes actually benefit from being eaten too! According to National Geographic, the parrotfish will clean nuisance algae from the corals, helping them keep healthy. The majority of fish that eat coral do not harm the overall ecosystem of the reef, but rather are necessary for keeping it healthy and stable.
Coral as Protection
Coral reefs are home to some amazing examples of symbiotic relationships. According to National Geographic, a symbiotic relationship is where two or more organisms that are different have a relationship or interaction. There are different types of symbiotic relationships. Mutualism is where both of the parties gain from the relationship, however, some symbiotic relationships are parasitic, where one creature will get harmed. Another type of symbiosis is commensalism, where one creature benefits but the other is not harmed.
Mutualism is rife in coral reefs, with fish, corals, and inverts all helping each other out and working together. One famous symbiotic relationship within coral reefs is the relationship between clownfish and anemones. Here, the anemones will provide shelter and protection to the clownfish. The anemone gains from the relationship from gaining food from the clownfish and being protected from larger predators.
This is just one of the ways in which coral reefs provide protection to fish. Smaller fish in the reef will often hide in and amongst corals, out of sight from their predators. This is why coral reefs are home to many species of small fish, as they provide so many hiding spots for the animals. Gobies, for example, will spend their time hiding in the crevices of the rockwork or in the sand, looking out for predators.
Because of the safety of coral reefs, it has been found that certain patches of coral are used as nurseries for juvenile fish. According to a study conducted by scientists from NOAA’s National Centers for Coastal Ocean Science, large numbers of juvenile grouper fish have been found in deepwater patches of finger-like coral. These patches of coral are dense and provide the smaller fish with much more protection than the rest of the reef. As many species of groupers are endangered, this gives us hope that we can work to protect these nurseries, and therefore the grouper fish.
In the Ocean, Everything is Connected
Coral reefs are home to so many different fish, however, the fish that live on coral reefs are not the only species that will be affected by coral reef bleaching. Everything in the ocean is connected, as the fish that live on coral reefs are eaten by larger fish, such as sharks. If there are no coral reefs to house the smaller fish, there will be no smaller fish to eat and therefore the larger predators will starve.
A lot of the predatory fish in the oceans rely on the coral reefs in some way. A lot of species of sharks will feed off smaller reef fish. These top predators are essential to the marine life food chain and the stability of the oceans. However, according to the World Wide Fund for Nature, many species of sharks are under grave threat. The damage to the habitats of sharks is adding to the declining numbers.
Everything in the ocean is linked, and if you remove a part of the food chain, every animal is affected. The wonderful creatures of the ocean are all under threat because of coral reef bleaching.
What Can We Do?
In order to protect the amazing ecosystems in the ocean, we need to speak out about the environmental issues that are affecting them. Coral reefs are dying because of bleaching which is caused by changes in the environment, such as rising temperatures and pollution. They are also under threat because of overfishing and coral mining.
These are caused by human interaction, and therefore we must raise awareness and put pressure on policymakers. We must act now to protect the coral reefs and all the marine life that rely on them.